/* 
    每一格的长度和宽度：15px
    一共有：40格
    总长度：15*40=600px
    边框宽度：20px
*/

#border {
    width: 600px;
    height: 600px;
    background-color: #ddd;
    margin: 30px auto;
    border: 20px solid rgb(68, 65, 65);
    position: relative;
    background-image: url('../images/bgd.webp');
    background-size: contain;
}

#border #start {
    width: 240px;
    height: 200px;
    background-image: url("../images/start.png");
    background-repeat: no-repeat;
    margin: 0 auto;
    margin-top: 180px;
    position: relative;
    /* z-index只能用在定位元素上 */
    z-index: 9;
    /* display: none; */
}

#border #lose {
    width: 200px;
    height: 200px;
    background-color: red;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    margin: auto;
    background-image: url("../images/bgd.jfif");
    background-size: contain;
    background-repeat: no-repeat;
}